Ladder tests?

[CC11]

So to start, I'm getting ready to work up a load for my 28 Nosler, shooting Nosler brass, Fed215s, Retumbo and the Berger hybrid 190s, and had a couple of questions. In the past with my guns I've always found my max COAL for my gun, then jumped the bullet to start work up and went with groups of 3, increasing powder until I found a good load or showed signs of pressure. Then upon finding what looked like a good load, taken it out to 300 yards and done 5 shot groups in smaller powder increments until it is dialed, sometimes having to tweak the seating depth. This has worked out relatively well for me in the past, but after a bunch of reading I'm leaning towards trying a ladder test with this gun. My question is if I go this route and start my powder charge at the recommended start, and work up by say .3 grains, where do I start with my COAL? It's my understanding that once you find a powder node, you adjust seating depth to fine tune. But I know that some guns like the bullet jumped more than being jammed into the lans.

Or I could go the opposite way and follow Berger's recommendation and find seating depth first. Which is load up groups of 3, starting just jumped off the lans and jumping each group more. Then once finding the node that way, you would do a ladder test with powder to find your sweet spot. Am I missing anything here or thinking about it wrong? Thanks for the input!

 

[nhyrum]

I'd just start your ladder test at something like 30 thou off. That should give you a reasonable chance of the bullet at least halfway liking the jump, get your load, then fine tune seating depth.

Sent from my SM-G996U using Tapatalk

 

[mfllood3800]

Bergers in my rifles like to be seated tight. I would start at .010, find the obvious velocity node, and fine tune that on next trip out. Then fine tune seating depth if needed. My 28 Nos liked to go fast and really really fast and pressure crazy fast. I had 3 nodes with Retumbo pushing 175's, F215MG, and Bertram Brass. .

 

[doverpack12]

I would use an increment more coarse than 0.3 gr until you find pressure and approximate node/s then come back with a finer increment ladder.
I actually go 1 gr until I get 2-3 gr from book box then 0.5 gr to pressure and try for no more than 12 shots.
Best to load up 2 of each charge to help prevent chasing your tail.
Unknown Munitions did a workup series on here and claimed once you are in the powder node they don’t see that change when you adjust seating.

 

[Harvey_NW]

If mag length isn't a limitation I prefer to consider case density in relation to powder (if possible) and pick roughly where I'd like to be with seating depth, which is between the bottom edge of the bearing surface at the neck shoulder junction, and being seated at least a calibers depth into the case neck. If .050" off the lands gets me within those parameters I just start there. Then shoot a powder ladder in .3/4gr increments to identify a potential velocity node. Then shoot an OCW test within that charge window and see how consistent velocities are. Then fine tune seating depth from there.

Here's a load development thread I did on a new rifle recently with all the numbers and pictures, if you're interested. https://www.rokslide.com/forums/threads/280-ackley-improved-162gr-eld-m-h4831sc.237489/#post-2308351

 

[CC11]

Mag length won't be an issue since I'm using the Wyatt's extended box. Thanks guys for replying, I'm excited to get to the range and try finding the load this way! I'll report back with my findings

 

[Travis Bertrand]

I do OCW test first and load everything .060off. I go in .2 gr increments and do this three times shooting 1 string, then the next, then the next. (NOT 58.2, 58.2 ,58.2, 58.4, 58.4, 58.4 etc.). I then graph that using @Unknown Munitions reloading tool free on his website. I graph all three strings and look for my velocity node(s). I then find the node I want, then load for accuracy by adjusting seating depth. I will load .010, .030, .060. .090, and .120 off the lands. That will give a good direction on where to fine tune from in .005 or .01 increments.

 

[EdP]

I prefer to start with a moderate load .005 off the lands (using a bullet comparator measuring base too ogive) then increase the jump to .010, .015 and .020, 5 shots each over a chronograph. .005 off should avoid the pressure spike caused by being on or too close to the lands. One of these jumps usually gives me a group quite a bit better than the others and I work powder charges up in .5 grains from there. Again, 5 shot groups over a chronograph. My goal is to find the jump that works for the rifle/bullet combo then seek a velocity node. It works for me using tangent ogive bullets. Others have other methods that work for them. The chrono data should guide you towards the best answer but barrel harmonics play a part in group size too, so the best group and the best data are not always with the same load, but should be close.